.connection {
  overflow: visible;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.connection path {
  transition: stroke-width 0.2s ease;
  filter: drop-shadow(0 0 0 transparent);
  pointer-events: all;
}

.connection path:hover {
  stroke-width: 3px;
  filter: drop-shadow(0 0 3px rgba(66, 153, 225, 0.5));
}

.connection path[stroke="#4299e1"] {
  stroke-width: 4px;
  filter: drop-shadow(0 0 6px rgba(66, 153, 225, 0.8));
}

.line-selected {
  stroke-width: 4px;
  filter: drop-shadow(0 0 6px rgba(66, 153, 225, 0.8));
}

.line-normal {
  stroke-width: 2px;
  filter: drop-shadow(0 0 3px rgba(66, 153, 225, 0.5)); 
}